APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

7 Jun 1999

Volume 74, Issue 23, pp. 3429-3577

Page 1 of 3 Pages Next Page | Jump to Page
back to top
RSS Feeds

All-optical focal length converter using large optical nonlinearity in guest-host liquid crystals

Hiroshi Ono and Yoshiro Harato

Appl. Phys. Lett. 74, 3429 (1999); http://dx.doi.org/10.1063/1.124117 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present an all-optical focal length converter using both large optical nonlinearity and anisotropic complex refractive indices in guest-host nematic liquid crystals (GHLCs). The nonlinear phase modulation was generated by irradiating the GHLCs with a He–Ne laser beam (wavelength; 633 nm) having a Gaussian profile. A laser diode (LD) beam (wavelength; 788 nm) passed at the same point as the He–Ne laser beam spot. The phase of the LD beam was modulated and the LD beam was focused due to the phase modulation. The focal length of the LD beam was varied over a range of several centimeters by controlling the intensity of the He–Ne laser beam. © 1999 American Institute of Physics.
Show PACS
42.79.Kr Display devices, liquid-crystal devices
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
42.60.Fc Modulation, tuning, and mode locking
42.70.Df Liquid crystals

Far-infrared laser oscillation from a very small p-Ge crystal under uniaxial stress

N. Hiromoto, I. Hosako, and M. Fujiwara

Appl. Phys. Lett. 74, 3432 (1999); http://dx.doi.org/10.1063/1.124118 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on pulse laser oscillation from a p-Ge intervalence band (IVB) laser composed of a Ga-doped Ge crystal measuring about 1×1×5 mm3 which is a very small volume compared with those reported so far for shallow-acceptor-doped Ge. Laser oscillation is only achieved under uniaxial stresses greater than 1300 kg/cm2. We find that the optimum stress for lasing is around 3500–4100 kg/cm2 when the p-Ge IVB lasers are operated at liquid helium temperature. The minimum electric power needed for lasing is only 280 W at a peak period of pulse emission. © 1999 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.72.Ai Infrared sources
42.60.Rn Relaxation oscillations and long pulse operation
71.55.Cn Elemental semiconductors
71.20.Mq Elemental semiconductors

Polarization modulation in optoelectronic generation and detection of terahertz beams

Q. Chen and X.-C. Zhang

Appl. Phys. Lett. 74, 3435 (1999); http://dx.doi.org/10.1063/1.124119 (3 pages) | Cited 27 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Compared with the conventional laser amplitude modulation with a lock-in amplifier, the optical polarization modulation in optoelectronic generation and detection of a free-space terahertz (THz) radiation provides up to twofold increase of the dynamic range. The total laser power for the optoelectronic generation of THz beams can be fully utilized. © 1999 American Institute of Physics.
Show PACS
42.79.Hp Optical processors, correlators, and modulators
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
42.65.Re Ultrafast processes; optical pulse generation and pulse compression

InAsSb/InAsP strained-layer superlattice injection lasers operating at 4.0 μm grown by metal-organic chemical vapor deposition

B. Lane, Z. Wu, A. Stein, J. Diaz, and M. Razeghi

Appl. Phys. Lett. 74, 3438 (1999); http://dx.doi.org/10.1063/1.124120 (3 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report high power mid-infrared electrical injection operation of laser diodes based on InAsSb/InAsP strained-layer superlattices grown on InAs substrate by metal-organic chemical vapor deposition. The broad-area laser diodes with 100 μm aperture and 1800 μm cavity length demonstrate peak output powers of 546 and 94 mW in pulsed and cw operation respectively at 100 K with a threshold current density as low as 100 A/cm2. © 1999 American Institute of Physics.
Show PACS
42.60.By Design of specific laser systems
42.55.Px Semiconductor lasers; laser diodes
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
81.15.Kk Vapor phase epitaxy; growth from vapor phase
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
81.05.Ea III-V semiconductors

A vertical cavity light emitting InGaN quantum well heterostructure

Y.-K. Song, H. Zhou, M. Diagne, I. Ozden, A Vertikov, A. V. Nurmikko, C. Carter-Coman, R. S. Kern, F. A. Kish, and M. R. Krames

Appl. Phys. Lett. 74, 3441 (1999); http://dx.doi.org/10.1063/1.124121 (3 pages) | Cited 32 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A method is described for fabricating a vertical cavity light emitting structure for nitride semiconductors. The process involves the separation of a InGaN/GaN/AlGaN quantum well heterostructure from its sapphire substrate an its enclosure by a pair of high reflectivity, low loss dielectric mirrors to define the optical resonator. We have demonstrated a cavity Q factor exceeding 600 in initial experiments, suggesting that the approach can be useful for blue and near ultraviolet resonant cavity light emitting diodes and vertical cavity lasers. © 1999 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
85.60.Jb Light-emitting devices
42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Indium tin oxide thin films for organic light-emitting devices

H. Kim, A. Piqué, J. S. Horwitz, H. Mattoussi, H. Murata, Z. H. Kafafi, and D. B. Chrisey

Appl. Phys. Lett. 74, 3444 (1999); http://dx.doi.org/10.1063/1.124122 (3 pages) | Cited 106 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
High-quality indium tin oxide (ITO) thin films (150–200 nm) were grown on glass substrates by pulsed laser deposition (PLD) without postdeposition annealing. The electrical, optical, and structural properties of these films were investigated as a function of substrate temperature, oxygen pressure, and film thickness. PLD provides very uniform ITO films with high transparency (⩾85% in 400–700 nm spectrum) and low electrical resistivity (2–4×10−4 Ω cm). The Hall mobility and carrier density for a 170-nm-thick film deposited at 300 °C are 29 cm2/V s and 1.45×1021 cm−3, respectively. Atomic force microscopy measurements of the ITO films indicated that their root-mean-square surface roughness (∼5 Å) is superior to that (∼40 Å) of commercially available ITO films deposited by sputtering. ITO films grown at room temperature by PLD were used to study the electroluminescence (EL) performance of organic light-emitting devices. The EL performance was comparable to that measured with commercial ITO anodes. © 1999 American Institute of Physics.
Show PACS
73.61.Le Other inorganic semiconductors
78.66.Li Other semiconductors
85.60.Jb Light-emitting devices
68.55.-a Thin film structure and morphology
81.15.Fg Pulsed laser ablation deposition
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
68.35.B- Structure of clean surfaces (and surface reconstruction)
78.60.Fi Electroluminescence
81.05.Hd Other semiconductors

Response of 1.6 μm Er:Y3Al5O12 fiber-optic temperature sensor up to 1520 K

D. M. Henry, J. H. Herringer, and N. Djeu

Appl. Phys. Lett. 74, 3447 (1999); http://dx.doi.org/10.1063/1.124123 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Fiber-optic temperature sensors based on fluorescence decay of the 1.6 μm transition in Er:Y3Al5O12 (Er:YAG) have been operated up to 1520 K. The probes are of a monolithic construction consisting of a single-crystal YAG lead fiber and an Er:YAG tip. The temperature-dependent fluorescence decay data show the dominance of the phonon mode at 220 cm−1 in mediating multiphonon relaxation in YAG at high temperatures. Such a sensor was used in the direct measurement of temperature in the interior of molten aluminum. © 1999 American Institute of Physics.
Show PACS
42.81.Pa Sensors, gyros
07.60.Vg Fiber-optic instruments
07.20.Dt Thermometers
07.20.Ka High-temperature instrumentation; pyrometers
78.55.Hx Other solid inorganic materials
63.20.K- Phonon interactions

Measurements of the THz absorption and dispersion of ZnTe and their relevance to the electro-optic detection of THz radiation

G. Gallot, Jiangquan Zhang, R. W. McGowan, Tae-In Jeon, and D. Grischkowsky

Appl. Phys. Lett. 74, 3450 (1999); http://dx.doi.org/10.1063/1.124124 (3 pages) | Cited 69 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Via THz time-domain spectroscopy, we have measured the absorption and index of refraction of single-crystal 〈110〉 ZnTe from 0.3 to 4.5 THz. We find that the absorption is dominated by two lower-frequency phonon lines at 1.6 and 3.7 THz and not by the transverse-optical (TO) -phonon line at 5.3 THz as previously assumed. However, the index of refraction is determined mainly by the TO-phonon line. Using these data, we discuss a frequency-domain picture of electro-optic detection of THz radiation below the TO-phonon resonance and compare with the photoconductive THz receiver over the same frequency range. © 1999 American Institute of Physics.
Show PACS
78.30.Fs III-V and II-VI semiconductors
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.20.Jq Electro-optical effects
78.47.-p Spectroscopy of solid state dynamics
63.20.-e Phonons in crystal lattices
85.60.Gz Photodetectors (including infrared and CCD detectors)

Investigation of nanolocal fluorescence resonance energy transfer for scanning probe microscopy

G. T. Shubeita, S. K. Sekatskii, M. Chergui, G. Dietler, and V. S. Letokhov

Appl. Phys. Lett. 74, 3453 (1999); http://dx.doi.org/10.1063/1.124125 (3 pages) | Cited 11 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Fluorescence resonance energy transfer (FRET) has been observed between donor dye molecules deposited onto the sample surface and acceptor dye molecules deposited onto the scanning near-field optical microscope (SNOM) or atomic force microscope tip. FRET was observed only when the tip acquired a contact with the sample and took place in a region of few tens of square nanometers in size when thousands (hundreds) of molecules are involved. In view of the obtained results, the perspectives for the construction of a one-atom FRET SNOM are described. © 1999 American Institute of Physics.
Show PACS
07.79.Fc Near-field scanning optical microscopes
07.79.Lh Atomic force microscopes
33.50.Dq Fluorescence and phosphorescence spectra
78.55.Kz Solid organic materials

Nanocrystalline titanium dioxide-dispersed semiconducting polymer photodetectors

K. S. Narayan and Th. B. Singh

Appl. Phys. Lett. 74, 3456 (1999); http://dx.doi.org/10.1063/1.124126 (3 pages) | Cited 18 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Photodetection properties of nanocrystalline titanium dioxide, TiO2, dispersed in poly-2-methoxy-5-(2′-ethyl-hexoxy)-1,4 paraphenylenevinylene MEHPPV are studied. Responsivity as high as 50 mA/W is observed in the single-layered composite device. The spectral response is sensitive to the magnitude of the bias in the low-voltage range and the crossover from a symbatic to antibatic response is closely followed. At higher reverse bias, the response is relatively uniform throughout the entire spectral range. Differences in the switching response in the forward bias and reverse bias are observed with a pronounced effect of the persistence photocurrent in the forward bias. © 1999 American Institute of Physics.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
72.40.+w Photoconduction and photovoltaic effects
81.07.-b Nanoscale materials and structures: fabrication and characterization

Photorefractive Bragg gratings in nematic liquid crystals aligned by a magnetic field

Gary P. Wiederrecht and Michael R. Wasielewski

Appl. Phys. Lett. 74, 3459 (1999); http://dx.doi.org/10.1063/1.124127 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Photorefractive Bragg gratings are observed in low-molar-mass nematic liquid crystals doped with electron donor and acceptor molecules. This is accomplished by alignment of the nematic liquid crystals in a 0.3 T magnetic field, which produces thicker homeotropic aligned samples than traditional surfactant techniques. Grating fringe spacings as low as 3.7 μm are achieved with 176-μm-thick samples, producing grating Q values of 33. Up to this point, low molar mass nematic liquid crystals have exhibited photorefractive gratings with Q ⩽ 1. Asymmetric two-beam coupling and photoconductivity experiments are performed to verify the photorefractive origin of the gratings. © 1999 American Institute of Physics.
Show PACS
42.79.Dj Gratings
42.70.Df Liquid crystals
42.70.Gi Light-sensitive materials
61.30.Gd Orientational order of liquid crystals; electric and magnetic field effects on order
42.79.Kr Display devices, liquid-crystal devices
72.40.+w Photoconduction and photovoltaic effects
back to top
RSS Feeds

Bias-enhanced nucleation and growth of the aligned carbon nanotubes with open ends under microwave plasma synthesis

S. H. Tsai, C. W. Chao, C. L. Lee, and H. C. Shih

Appl. Phys. Lett. 74, 3462 (1999); http://dx.doi.org/10.1063/1.124128 (3 pages) | Cited 64 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Aligned carbon nanotubes with open ends have been fabricated on silicon wafer in one step using a microwave plasma enhanced chemical vapor deposition system with a mixture of methane and hydrogen as precursors. High concentration hydrogen plasma and high negative bias voltage to the substrate induce anisotropic etching of carbon nanotubes and can effectively reduce the randomly oriented carbon nanotubes. The mechanism of aligned carbon nanotubes with open ends is proposed in this letter. © 1999 American Institute of Physics.
Show PACS
61.48.-c Structure of fullerenes and related hollow and planar molecular structures
81.05.ub Fullerenes and related materials
81.20.-n Methods of materials synthesis and materials processing
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Study of ground-state titanium ion velocity distributions in laser-produced plasma plumes

G. W. Martin, I. Weaver, T. P. Williamson, A. H. El-Astal, D. Riley, M. J. Lamb, T. Morrow, and C. L. S. Lewis

Appl. Phys. Lett. 74, 3465 (1999); http://dx.doi.org/10.1063/1.124129 (3 pages)

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The velocity distribution of ground-state titanium ions within a low-temperature plasma resulting from the laser ablation of a titanium target has been investigated. A KrF excimer laser was focused onto the target at moderate fluences (<10J cm−2) in vacuum ( ∼ 2×10−5 Torr). Time-of-flight distributions were determined as functions of distance from target and laser fluence using absorption spectroscopy. The results were found to be described consistently by a Maxwell–Boltzmann distribution with zero flow velocity. The most probable velocity was found to scale with the square root of the incident laser fluence. © 1999 American Institute of Physics.
Show PACS
52.70.Nc Particle measurements
79.20.Ds Laser-beam impact phenomena
81.65.-b Surface treatments

Guiding radio frequency waves on metallic foils

M. Friedman and R. F. Fernsler

Appl. Phys. Lett. 74, 3468 (1999); http://dx.doi.org/10.1063/1.124130 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The propagation of electromagnetic surface waves along thin metallic strips was investigated. Efficient guidance of surface waves over distances of many kilometers can now be realized since: (1) low attenuation of the electromagnetic waves can be achieved by increasing the width of the strip, (2) losses by scattering are small because of the large reduction in the radial extension of the electric field, and (3) thin foils are lightweight. Other means (e.g., coaxial line or waveguides) of transporting electromagnetic waves produce orders of magnitude increase in weight, cost, and attenuation. © 1999 American Institute of Physics.
Show PACS
41.20.Jb Electromagnetic wave propagation; radiowave propagation
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

Patterning of cubic and hexagonal GaN by Cl2/N2-based reactive ion etching

J. Fricke, B. Yang, O. Brandt, and K. Ploog

Appl. Phys. Lett. 74, 3471 (1999); http://dx.doi.org/10.1063/1.124131 (3 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Chlorine-based dry etching of hexagonal and cubic GaN epilayers grown by dc plasma-assisted molecular beam epitaxy is investigated using a conventional parallel electrode reactor. It is found that the addition of nitrogen results in a shallow maximum for etch rates at 37% N2 content in a low-pressure plasma and a monotonically decreasing etch rate in higher-pressure plasmas. Etching with a low-pressure plasma produces smooth surfaces and almost vertical sidewalls at sufficiently high etch rates. © 1999 American Institute of Physics.  
Show PACS
81.05.Ea III-V semiconductors
81.65.Cf Surface cleaning, etching, patterning
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition
back to top
RSS Feeds

Flow dynamics of sheared liquids explored by inelastic neutron scattering

A. Magerl, H. Zabel, B. Frick, and P. Lindner

Appl. Phys. Lett. 74, 3474 (1999); http://dx.doi.org/10.1063/1.124132 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have applied high resolution neutron spectroscopy to elucidate the dynamics of sheared liquids. At room temperature, the macroscopic flow of the lubricant yields a peak of the scattered intensity at roughly half the velocity of the driving disk demonstrating a nonclassical flow, whereas at higher temperature the expected linear velocity profile establishes. The data also give information on a modification of local diffusion modes for a liquid in a shear field. © 1999 American Institute of Physics.
Show PACS
47.50.-d Non-Newtonian fluid flows
83.50.Ax Steady shear flows, viscometric flow
61.05.fg Neutron scattering (including small-angle scattering)
63.50.-x Vibrational states in disordered systems
66.10.C- Diffusion and thermal diffusion

Threshold behavior analysis of in-plane switching mode liquid-crystal cells with asymmetrical surface condition

Makoto Yoneya and Katsumi Kondo

Appl. Phys. Lett. 74, 3477 (1999); http://dx.doi.org/10.1063/1.124133 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The threshold behavior of the in-plane switching (IPS) mode liquid-crystal cells with different (asymmetric) anchoring strength at two liquid-crystal/substrate interfaces was investigated by linear stability analysis. Similarity in stability characteristics between the IPS mode and the surface stabilized ferroelectric mode was clarified. The analysis showed that, with parallel rubbing of the two substrate surfaces, only the (symmetric) switching initialized from the center of the liquid-crystal layer will occur even with the asymmetric surface condition. This means that the basic switching process of the IPS mode does not change with the asymmetricities of the surface conditions. © 1999 American Institute of Physics.
Show PACS
42.79.Kr Display devices, liquid-crystal devices
61.30.Gd Orientational order of liquid crystals; electric and magnetic field effects on order
61.30.Cz Molecular and microscopic models and theories of liquid crystal structure

Infrared absorption of Li acceptors and shallow donors in ZnSe

H. Nakata, K. Yamada, and T. Ohyama

Appl. Phys. Lett. 74, 3480 (1999); http://dx.doi.org/10.1063/1.124134 (3 pages) | Cited 6 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using Fourier transform infrared spectroscopy, we have observed the absorption spectra of holes bound to acceptors in bulk ZnSe below 100 K. The absorption is assigned to hole transition of Li acceptors from the 1S3/2 ground state to the 2P3/2 excited state. The obtained transition energy of 72.9±0.1 meV is one order more precise than that obtained by photoluminescence measurements. In addition, absorption lines due to shallow donors are observed below 30 K, and the intensity is enhanced by excitation with a blue light emitting diode. The 1s–2p transition energies of three kinds of donors Al, Cl, and In are estimated at 18.96, 19.64, and 21.67 meV, respectively. © 1999 American Institute of Physics.  
Show PACS
78.30.Fs III-V and II-VI semiconductors
71.55.Gs II-VI semiconductors
78.66.Hf II-VI semiconductors

Revival of interband crystalline reflectance from nanocrystallites in porous silicon by immersion plating

Zain Yamani, A. Alaql, Joel Therrien, Osama Nayfeh, and Munir Nayfeh

Appl. Phys. Lett. 74, 3483 (1999); http://dx.doi.org/10.1063/1.124135 (3 pages) | Cited 9 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We prepared porous silicon for which the UV reflectance (3.3–6 eV) is nearly eliminated, and exhibits no features at the Si interband bulk transitions 3.3, 4.3, and 5.5 eV. Plating with a thin layer of copper is found to cause recovery of the UV bulk-like crystalline reflectance and interband resonances. This provides evidence that the loss of crystalline absorption is reversible and is not due to a permanent loss in the crystalline structure. This may relate to a recent model in which the optical activity of ultra small nanocrystallites is produced by a new Si–Si crystalline configuration (or phase), distinct from but interconnected to the diamond-like configuration by a potential barrier. © 1999 American Institute of Physics.
Show PACS
78.20.-e Optical properties of bulk materials and thin films
78.40.Fy Semiconductors
78.20.Ek Optical activity

Photoluminescence study of ZnS/ZnMgS single quantum wells

K. Ichino, K. Ueyama, H. Kariya, N. Suzuki, M. Kitagawa, and H. Kobayashi

Appl. Phys. Lett. 74, 3486 (1999); http://dx.doi.org/10.1063/1.124137 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report a photoluminescence (PL) study of ZnS/ZnMgS strained-layer single quantum wells. The main PL peak from ZnS is attributed to light-hole free excitons. Quantum confinement causes it to shift from 3.76 eV to higher energy, 3.84 eV, with decreasing well width. Hydrostatic and shear deformation potentials are determined from energies of light- and heavy-hole exciton emission, to be a = −6.4 eV and b = −1.0 eV, respectively. © 1999 American Institute of Physics.
Show PACS
78.66.Hf II-VI semiconductors
78.55.Et II-VI semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
71.35.Cc Intrinsic properties of excitons; optical absorption spectra
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)

Improvements in electrical properties of (Ba,Sr)TiO3 capacitor with chemical vapor deposited Pt top electrode using Pt hexafluoroacetylacetonate

Jong Myeong Lee, Sang Yeol Kang, Ju Cheol Shin, Won Joon Kim, Cheol Seong Hwang, and Hyeong Joon Kim

Appl. Phys. Lett. 74, 3489 (1999); http://dx.doi.org/10.1063/1.124139 (3 pages) | Cited 11 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electrical properties of (Bs,Sr)TiO3 (BST) thin films are characterized with sputtered and metal organic chemical vapor deposited (MOCVD) Pt top electrodes. BST films with MOCVD Pt top electrodes, which were deposited using Pt(CF3COCHCOCF3)2 (Pt-HFA) as a precursor, showed less leakage current without bulged curves and a higher dielectric constant than those with sputtered Pt top electrodes. The improvement of electrical properties seems to result from the reduction of interface trap sites with the incorporation of fluorine atoms from HFA ligands. © 1999 American Institute of Physics.
Show PACS
84.32.Tt Capacitors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.15.Cd Deposition by sputtering
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
77.22.Ch Permittivity (dielectric function)
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.20.At Surface states, band structure, electron density of states

Plasma-assisted pulsed laser deposition of SrBi2Ta2O9 thin films of improved ferroelectric and crystalline properties

A. C. Rastogi, S. Tirumala, and S. B. Desu

Appl. Phys. Lett. 74, 3492 (1999); http://dx.doi.org/10.1063/1.124140 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Significant effect of the introduction of O2-plasma discharge during pulsed laser ablative deposition of SrBi2Ta2O9 (SBT) films on improving the crystallite orientation and ferroelectric properties has been described. O2-plasma assists in the formation of highly crystalline films at a low 700 °C temperature over (111) oriented Pt films coated Si(100) single crystal substrates at a nominal pressure of 200 mTorr. Plasma excitation potential, applied at an auxiliary ring electrode placed near the substrate, has a profound effect on surface morphology, crystallite orientation, and remnant polarization, Pr values. At −350 V, SBT growth at 700 °C with predominant (a-b) orientation showing high Pr ∼ 6.5 μC/cm2 in the as-deposited state has been obtained. In comparison, SBT films deposited identically but without the plasma show a low Pr of ∼1.7 μC/cm2. Ionized cationic species along with ionic and atomic oxygen present in the plasma improve thermodynamic stability of the film growth through enhanced chemical reactivity and thus eliminates the need for any severe postgrowth crystallization anneal step in the synthesis of SBT films. Impingement of energetic O2 ions and atomic oxygen helps lower the nucleation barrier for the growth of (a-b) crystallites and changes the c-axis orientation from normal to near parallel to the film plane. Quality of the film declines with the plasma excitation potential as enhanced kinetic energy of impinging O2 ions introduce defects and reduce nucleation density by resputtering from the substrate. © 1999 American Institute of Physics.
Show PACS
77.80.-e Ferroelectricity and antiferroelectricity
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.55.-g Dielectric thin films
81.15.Fg Pulsed laser ablation deposition
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition
68.55.-a Thin film structure and morphology
68.35.B- Structure of clean surfaces (and surface reconstruction)
77.22.Ej Polarization and depolarization

High conduction-band offset of AlInAsSb/InGaAs multiple quantum wells grown by metalorganic vapor phase epitaxy

J. R. Chang, Y. K. Su, C. L. Lin, K. M. Wu, Y. T. Lu, D. H. Jaw, H. P. Shiao, and W. Lin

Appl. Phys. Lett. 74, 3495 (1999); http://dx.doi.org/10.1063/1.124141 (3 pages) | Cited 7 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Unstrained Al0.66In0.34As0.85Sb0.15/In0.53Ga0.47As multiple-quantum-well (MQW) structures have been grown by metalorganic vapor phase epitaxy. Low-temperature photoluminescence was performed for these MQW structures. We compared the experimental data with the theoretical calculations. The conduction-band offset ratio of AlInAsSb/InGaAs heterojunction was set as an adjustable parameter in the theoretical model. We estimated the conduction-band offset ratio to be 0.90±0.05 for the Al0.66In0.34As0.85Sb0.15/In0.53Ga0.47As heterojunction. © 1999 American Institute of Physics.
Show PACS
73.20.At Surface states, band structure, electron density of states
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
81.15.Kk Vapor phase epitaxy; growth from vapor phase
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors

Optical properties of β-Si3N4 single crystals grown from a Si melt in N2

F. Munakata, K. Matsuo, K. Furuya, Y. Akimune, J. Ye, and I. Ishikawa

Appl. Phys. Lett. 74, 3498 (1999); http://dx.doi.org/10.1063/1.124142 (3 pages) | Cited 33 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Large colored β-Si3N4 single crystals were successfully grown from a Si melt in N2. The transmission optical absorption of coloring β-Si3N4 single crystal shows that impurities introduce a midgap level of ∼2.4 eV into the wide band gap of ∼5.3 eV in nondoped Si3N4. The infrared transmission spectrum and electron probe x-ray microanalysis of β-Si3N4 samples show that the solution of the Al element affects the silicon–nitrogen molecular vibration and the states within the band gap of β-Si3N4. The obtained results mean that the Al impurity acts as the radiative center and is the origin of the color in the β-Si3N4 single crystal. © 1999 American Institute of Physics.
Show PACS
78.40.Ha Other nonmetallic inorganics
78.30.Hv Other nonmetallic inorganics
81.10.Fq Growth from melts; zone melting and refining
71.55.Ht Other nonmetals
63.20.-e Phonons in crystal lattices

Ion-channeling study of the SiC/Si/SiO2/Si interface

W. Jiang, S. Thevuthasan, W. J. Weber, and F. Namavar

Appl. Phys. Lett. 74, 3501 (1999); http://dx.doi.org/10.1063/1.124143 (3 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Ion channeling has been used in a detailed study of 3C–SiC films grown by chemical vapor deposition on a Si/SiO2/Si substrate. For a 160-nm-thick 〈100〉-oriented SiC film, the results show a minimum yield (χmin) of ∼ 28% at the SiC–Si interface, while a SiC film with a thickness of ∼ 2.4 μm, grown under identical conditions, was almost defect free (χmin = 5.3%) in the surface region. Angular scans around the 〈110〉 axis revealed the existence of a superlattice structure at the SiC–Si interface. The strain-induced angular shift was determined to be 0.16°±0.05°, indicating a kink between the SiC and Si layers along the inclined 〈110〉 axis. A modified model is suggested to interpret the experimental observations. © 1999 American Institute of Physics.
Show PACS
68.35.Ct Interface structure and roughness
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
61.85.+p Channeling phenomena (blocking, energy loss, etc.)
81.05.Hd Other semiconductors
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
82.80.Yc Rutherford backscattering (RBS), and other methods of chemical analysis
Page 1 of 3 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close